In a plastic chain that includes a plurality of chain elements, the respective chain elements are connected to one another by way of shafts perpendicularly arranged with respect to the longitudinal axis of the plastic chain. However, the shafts have to be locked in place to keep the chain assembled. Utilizing separate chain elements allows for the assembly of chains of various widths and so on. Additionally, the chain normally has to be guided both laterally and horizontally. Thus, it can be seen that limiting factors with respect to flexibility concerning chain variations include, on the one hand, the locking of the shaft and on the other hand, the guiding of the chain by guiding means.
As far as the locking of the shafts is concerned, the state of the art presents in principle two solutions. In accordance with one solution, plastic shafts are used. In this case, a common way of locking the shaft in place is to deform the end of the shaft by melting. The use of this technique, however, naturally results in the shafts not being reusable. Moreover, dismantling the chain elements becomes more difficult in that a destruction of the shaft (or the chain element) is required.
Another solution involves the use of steel shafts. These steel shafts can be machined in any suitable way and then locked in place by way of locking washers or the like. (See, for example, U.S. Pat. No. 4,832,187 or EP-A 288,409). In either of the aforementioned cases, the flexibility is severely limited and the production becomes more expensive.
For guiding plastic chains and for maintaining them in place, guiding pins are used. These guiding pins can be designed to guide a chain both laterally and vertically in relation to the plane of movement. Already known solutions, however, only employ guiding pins that are cast or otherwise manufactured in one piece with the chain element. The guiding pin is thereby fixed in one particular position with respect to the chain. The possibility of using one and the same chain element in chains with different shapes and of different types is thereby limited. In order to manufacture as large a variety of plastic chains as desired, a multitude of different variations of the chain element is required.